DNAAF2 and primary ciliary dyskinesia: In 2008, two heterozygous variants c.C23A [pS8X] and c.1214-1215insACGATACCTGCGTGGC [p.G406Rfs89X] variants of DNAAF2 were first identified in two consanguineous families with PCD presented with recurrent respiratory tract infections, laterality defects and impaired fertility [6].